I was writing something very similar a few hours back.
Ability to import a dashboard (with additional updates/changes) onto existing dashboard, instead of creating a new dashboard every time.
Once we roll out an Atlas dashboard embedded into our product, any small change would require us to reimport the .charts from dev environments through higher environments. This leads to creation of new dashboard, thus a new embedding id, which is also required to be changed in our embedding code/config and call for a redeployment.
It would beneficial, if during import of .charts - if a dashboard with same name is found, the user is given an ability to overwrite existing dashboard (with keeping the existing embedding ids for dashboard, and it’s existing charts) OR import it as a new one. With an overwrite option, which won’t change the embedding ids - nothing needs to change on applications embedding the dashboard/charts - making such changes simple & easy.